Income Taxes Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 25, 2021	Dec. 26, 2020
Deferred tax assets:
Inventories	$ 2,316	$ 2,061
Retirement benefits	824	1,126
State net operating losses	3,033	3,305
Federal net operating losses	0	556
State tax credit carryforwards	1,669	1,688
Federal tax credit carryforwards	4,136	4,413
Allowances for bad debts, claims and discounts	1,779	1,874
Other	3,958	4,595
Total deferred tax assets	17,715	19,618
Valuation allowance	(12,851)	(14,202)
Net deferred tax assets	4,864	5,416
Deferred tax liabilities:
Property, plant and equipment	4,955	5,507
Total deferred tax liabilities	4,955	5,507
Net deferred tax liability	$ (91)	$ (91)